bug#47860: 28.0.50; Mini buffer resize when lines are truncated regression

[Eli Zaretskii]

> Date: Mon, 19 Apr 2021 20:40:40 +0300
> From: Eli Zaretskii <eliz@gnu.org>
> Cc: 47860@debbugs.gnu.org, gregory@heytings.org
> 
>   (progn
>     (with-current-buffer (get-buffer-create "foo")
>       (insert "test: ")
>       (overlay-put (make-overlay (point-max) (point-max))
>                  'after-string "
>   
> \naaa\nbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb\ncccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc")
>       (setq-local truncate-lines t))
>     (switch-to-buffer "foo")
>     (window-text-pixel-size))
> 
> The result indicates that the buffer has only 4 screen lines, whereas
> it actually has 5.

I hope I fixed this now on the master branch, please test.